Thermal Comfort in an Office error - multiple solid bodies

Trying to analyze Thermal Comfort of an Office room .
Error: Unable to achieve similar model as in the tutorial. Simulation is not running stating an error as multiple solid bodies.
Project link: https://www.simscale.com/workbench/?pid=8034042795258894707&mi=spec%3Ab469dfe5-cc9f-4a04-a4a0-a8ab4c5f4a05%2Cservice%3ASIMULATION%2Cstrategy%3A2

Hey there, I assume you are following one of our tutorials, right? can you also include the link to the original project?

The link to the project.

And yes I was following the tutorial.

And also how was that model done?

Now I am getting this as error.

Hey there, in order to simulate a convective heat transfer case, you will need to have a single region that represents the fluid material. Here you have 4 different parts:

So you will have to merge all the outer walls together, then create an open inner region as described here:

Also, if you are facing issues with another project, feel free to add a separate forum post for this, I will be happy to help you there!

Best regards,
Fillia